Timer with internal stop mechanism comprising annular ring structure interfitting complementary housing member

ABSTRACT

A stop means is sandwiched between two members carried by a rotating shaft, the stop means cooperating with a lug carried by one of the members to limit the shaft&#39;&#39;s rotation.

United States Patent 1 3,699,277 Straub [4s] Oct.17, 1972 (541 TIMER WITH INTERNAL STOP MECHANISM COMPRISING ANNULAR RING STRUCTURE INTERFITTING COMPLEMENTARY HOUSING MEMBER Inventor: Paul J. Straub, Indianapolis, Ind.

Assignee: P. R. Mallory & Co., Inc., lndianapolis, Ind.

Filed: June 1 l, 1971 Appl. No.: 152,183

US. Cl ..200/38 R, 200/38 B, 200/168 R Int. CL ..H0lh 7/08, HOlh 43/10 Field of Seareh..200/38 B, 38 BA, 38 C, 38 CA,

[56] References Cited UNITED STATES PATENTS 3,500,005 3/1970 Brown ..200/38 B 3,579,264 5/1971 Mork et a] ..200/38 B X Primary Examiner-J. R. Scott Attorney-Richard H. Childress et al.

[5 7] ABSTRACT A stop means is sandwiched between two members carried by a rotating shaft, the stop means cooperating with a lug carried by one of the members to limit the shafts rotation.

11 Claims, 2 Drawing Figures PATENTEDUCT 17 1972 3 699 lNVENTOR PAUL J. STRAUB BWMMW ATTORNEY TIMER WITH INTERNAL STOP MECHANISM COMPRISING ANNULAR RING STRUCTURE INTERFITTING COMPLEMENTARY HOUSING MEMBER The present invention relates to timing mechanisms and more particularly to a timing mechanism which is neat and compact, and which utilizes a stop means which limits the rotational travel of the timer shaft.

Timing mechanisms are used in appliances such as washers, dryers, hair dryers, etc. to sequentially operate the appliance in accordance with a programmed sequence. In such mechanisms, cam programming means including cams carried by a shaft actuate electrical switches to provide the program sequence. The cam program means are usually driven through a motor drive means which usually includes a speed reduction means such as a gear train. In some instances, the amount of rotation of the shaft means needs to be limited in accordance with a predetermined program. Quite obviously, in such instances, means need to be provided to effect such limit to the shaft rotation. And in applications such as for hair dryers, the timing mechanism in addition to needing the stop means to limit the shafts rotation needs to be neat and compact with as little protrusions extending from the body of the timer as possible.

The present invention is concerned with timing mechanisms and has as one of its objects the provision of a timer which is neat and compact.

Another object of the invention is the provision of a timer which includes a means to limit the rotational travel ofthe timer shaft.

Still another object of the invention is the provision of a timer having a shaft means carrying at least two members, at least one of the members being a cam means wherein there is a stop means limiting the rotational travel of the shaft means sandwiched between the two members.

Yet another object of the invention is the provision of a timer having a cylindrical housing and wherein the stop means limiting the timer shaft rotation includes a ring disposed against a wall of the housing in a predetermined position and sandwiched between two members carried by the timer shaft, the ring having a stop arm engaging a stop lug carried by one of the members.

Still another object of the invention is the provision of a timer wherein the stop means includes a ring having a stop arm projecting therefrom, the ring being sandwiched between two members carried by a shaft, one of the members having a stop lug engaging the stop arm.

A further object of the invention is the provision of a timer having a cylindrical housing wherein contact blade retaining means are formed as part of the housing and wherein stop means limiting the timer shafts rotation includes a ring disposed against a wall of the housing in a predetermined position.

These and other objects of the invention will become apparent from the following description taken in conjunction with the accompanying drawings in-which:

FIG. l is an exploded view of a timing mechanism employing the features ofthe present invention;

FIG. 2 is a view taken along the line 2-2 of FIG. 1.

Generally speaking, the objects of the invention are accomplished by providing a timer wherein at least two members, one of which may be a cam means, are carried by a shaft means having a stop means sandwiched between the two members, the stop means cooperatively engaging a stop lug carried by one of the members. In particular, the housing for the timer is substantially cylindrical, with the stop means being a ring positioned against its wall, and having support means to locate and retain the ring in a predetermined position. The timer is neat and compact and has contact blade retaining means formed as part of the housing.

Referring now to FIG. 1, there is shown a timing device 10 incorporating the novel features of the present invention. The timer is composed of two subassemblies, the motor assembly 11 and the switch timing mechanism 12. The motor assembly includes a synchronous motor 9 and an appropriate gear train 8 which includes gear 7 driving the switch timing mechanism 12 through shaft 13 and motor pinion 6. Gear 7 is independently rotatably carried on shaft 13. The housing or cover for the switch timing mechanism includes a cup shaped member 14 and a cover plate 15 adapted to close the same. Cover plate 15 is securely fastened to a base plate of the housing for the gear train assembly through a plurality of screws 16 which engage internally threaded posts 16' and 16" extending through oblong shaped apertures 17. The cup shaped member 14 and the cover plate 15 are preferably fabricated of an electrically insulating material such as a phenolic plastic, for example.

The essential parts of the switch timing mechanism, in general, comprise switch contact blades 18 and 19 having electrical terminals 18 and 19' integrally formed as part of the blades, cam programming means 29, and contact blade retaining means 32 and 32' formed as an integral part of the cover 15 and cup shaped member 14. Cam programming means 29 includes at least one cam 29' fixedly carried by shaft 13. Shaft 13 is journalled in the base of cup shaped member 14 and in cover plate 15. For illustrative purposes, there is shown a step 30 provided in the cam, the step being formed in size and contour according to the desired program. As will be hereinafter described, such programming means will, with the proper selection of contact blades 18 and 19, and blade retaining means 32 and 32, allow various switching circuits to be readily obtained, the operation of such circuits being controlled by the timing of the cam programming means 29.

Contact blade 18 is responsive to the cam programming means through the wedge shaped cam follower 33, the follower being formed as an integral part of the blade. Blade 18, being responsive to the cam programming means, is the actuator blade. Movement of the blade 18 causes electrical contact 34 to engage contact 35. Suitable materials for the contact include an electrically conductive material such as copper, for example.

As illustrated in FIG. 1 the timing device of the present invention is adapted to give a single pole, single throw switching circuit arrangement. Cam programming means 29 forces blade 18 to rise when the wedge shaped cam follower 33 rides up and over the discrete arcuate step 30 thus opening contacts 34 and 35. Because of the contact blade retaining means 32 and 32 the blades readily return to their original position when cam follower 33 again reaches arcuate step 30. Blade retaining means 32 includes a stepped blade seating member 36 integrally formed with and extending from cover 15, notches 37 and 38 formed in cup shaped member 14, and L-shaped seating member 39 integrally formed with and extending from cup shaped member 14. Blade retaining means 32 includes an L- shaped seat member 40 and substantially rectangular shaped retaining member 41 both of which are integrally formed with and extending from cover 15, and L-shaped seat 42 and notches 43, 44 and 45 formed in cup shaped member 14.

When the various components of the retaining means are placed in their proper relationship by placing cover over the opening of cup shaped member 14, and when contact blades are inserted in slots formed by the inter-relationship of the parts, the contact blades will be cantilevered at one end with the other end blade 18 being free to bend in accordance with the actuation induced by cam programming means 29. When the menate step 30 of the cam programming means again reaches the cam follower 33, blade 18 will return thus making an electrical contact between contacts 34 and 35. Contact blade 18 preferably includes elongated apertures 18" which extends beyond the bend of the blade so that the blade can be more easily deflected for a given thickness of blade.

As is more clearly discussed in U. S. Pat. No. 3,500,005 Variable Circuit Timer" issued Mar. 10, 1970, to W. R. Brown, various switching sequences can be provided by providing various cams with various steps and by using a proper number of contact blades properly carried by the retaining means and the seating means.

Shaft 13 can be either motor driven or can be manually rotated so that a desired setting, such as the program starting point, may be manually set. In order that the manual rotation may be independent of the motor drive means, a clutch means 50 is provided. Clutch means 50 includes a pair of spring washers 51 and 52 fixedly carried on shaft 13 and frictionally engaging opposite faces of the gear 7 such that shaft 13 can be rotated when gear 7 is rotated through the motor drive. Shaft 13 can be manually rotated through the manual rotation overcoming the frictional engagement of the washers with the gear. However, according to the present invention the rotation of the shaft means will be limited. Such limitation is provided by stop means 54 having stop arm 53 cooperating with a stop lug 56 carried by cam 29'. Stop means 54 includes a ring 58 sandwiched between two members that are carried by shaft 13 (gear 7 and cam 29'). The ring surrounds a portion of the shaft 13 and is disposed adjacent to a wall of the cylindrical shaped housing provided by the cup-shaped member 14. Stop means 54 also includes support means 60 which locates and retains the ring in a predetermined position. Support means 60 includes a support arm 62, which includes a face 62' which is biased post 16" and a boss 62" which engages the posts corresponding oblong aperture 17; support arm 64, which includes a face 64' which is biased against post 16 and a boss 64 which engages oblong aperture 17; and arm 66 which engages the closed end 14- of cup-shaped member 14.

Upon rotation of cam 29', stop lug 56 engages stop arm 53 of stop means 54 to stop the rotational travel of the shaft 13.

What is claimed is:

1. A timer comprising:

a. drive means,

b. means coupling said drive means to a rotatable shaft means, including clutch means,

c. at least two members carried by said shaft, one of said members including cam means,

d. a housing means including a cylindrical wall substantially surrounding said shaft and said members,

e. a ring shaped stop means sandwiched between said two members, and a stop lug carried by one of said members cooperatively engaging a stop armprojecting from said stop means to limit the rotation of said shaft means, and

f. electrical switch means responsive to the rotation of said cam means.

2. A timer according to claim 1 wherein said stop means includes support means cooperating with said housing means locating and retaining said stop means in a predetermined position.

3. A timer according to claim 1 wherein said stop lug is carried by said cam means.

4. A timer according to claim 1 wherein said housing means includes bolt means securing a cover plate to an end of saidwall and said stop means further includes support means engaging said bolt means so as to locate and retain said stop means in a predetermined position.

5. A timer according to claim 4 wherein said stop means further includes support means engaging said cover plate to further locate and retain said stop means.

6. A timer according to claim 1 wherein the other of said two members is a gear of said means coupling said drive means to said shaft means.

7. A timer according to claim 6 wherein said clutch means includes a pair of spring washers, each carried on said shaft means, one each engaging a face of said gear.

3. A timer comprising:

a. a housing including a cup-shaped member and a cover adapted to .close the same,

b. a cam programming means including a shaft means carrying at least one cam,

c. retaining means integrally formed with said housing, 2

d. at least two contact blades carried by said retaining means so as to cantilever said contact blades, electrical contacts carried by said contact blades and adapted to engage one another,

e. cam follower means carried by one of said contact blades responsive to said cam programming means,

.- f. contact blade stop means disposed at the free ends of said blades,

g. motor drive means including a gear carried by said shaft adjacent said cam and clutch means said motor drive means applying power driven rotation to said shaft, and

h. a ring shaped stop means sandwiched between said gear and said cam, and a lug carriedby said cam cooperatively engaging a stop arm projecting from said ring shaped stop means to limit the rotation of said shaft means.

9. A timer according to claim 8 wherein at least one of said contact blades include elongated centrally disposed apertures.

10. A timer according to claim 8 wherein said contact blades are L-shaped, and at least one of said blades includes an elongated centrally disposed aperture extending past said bend.

11. A timer according to claim 9 wherein said contact blade retaining means comprises: an L-shaped seat formed in said cup shaped member, and L-shaped seat and a rectangular shaped member extending from said cover, and notches formed in said cup shaped member adapted to receive said L-shaped seat and said rectangular shaped member extending from said cover, insertion of said seat and said rectangular shape member in said notches providing slots receiving said contact blades to cantilever the same; and wherein said blade stop means comprises a stepped seating member extending from said cover, and notches and an L-shaped seat member formed in said cup shaped member, insertion of said stepped seating member into said notches providing a slot between said stepped seating member and said L-shaped seat member, said stepped seating member disposed to receive and stop at least one free end of said contact blades, and said slot adapted to receive an additional contact blade.

I UNITED STATES PATENT OFFICE CERTIFICATE OF (IQRRECTION Patent No- 699,277 7 Dated ioctober 17 1972 lnventofls) PAUL J STRAUB Itis certified .that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 5, line. 8; 1'9" should read 8 I Signed arid sealeddthis 1st day of May 1973.

'(ISAEAL) Attest: v

EDWARD M. FLETCHERJR. f ROBERT GOTTSCHALK.

Attesti ng Officer' I Y Commissioner of Patents USCOMM-DC scan-Pea U 5. GOVERNMENT PRINTING'OFFICE I969 0-366-33;

I I UNITED STATES? PATENT OFFICE CERTIFICATE OF CQIQRECTION Patent N'o- 599, 277 I Dated October 17, 1972 Inv n 'fl a PAUL J. STRAUB It is certified that error. appears in the above-identified patent and that; s aid Let ters Patent are hereby corrected as shown below:

Column 5, line 8; 9" should read 8 Si gned andv sealed this 1st day of MA 1973 I Y (SEAL Attest: I I

EDWARD M. F LE T CHER',J R. if I j 1 ROBERT GOTTSCHALK. I I I Attesting Off i-cer' I 1 I Commissioner of Patents Foe m p odoso fo-bm "I I .I 'I

I I I I I USCIO'MWDC 6037M";

' U. S. GOVERNjMENT PRINTING OFFICE I969 O-JSli-Silw 

1. A timer comprising: a. drive means, b. means coupling said drive means to a rotatable shaft means, including clutch means, c. at least two members carried by said shaft, one of said members including cam means, d. a housing means including a cylindrical wall substantially surrounding said shaft and said members, e. a ring shaped stop means sandwiched between said two members, and a stop lug carried by one of said members cooperatively engaging a stop arm projecting from said stop means to limit the rotation of said shaft means, and f. electrical switch means responsive to the rotation of said cam means.
 2. A timer according to claim 1 wherein said stop means includes support means cooperating with said housing means locating and retaining said stop means in a predetermined position.
 3. A timer according to claim 1 wherein said stop lug is carried by said cam means.
 4. A timer according to claim 1 wherein said housing means includes bolt means securing a cover plate to an end of said wall and said stop means further includes support means engaging said bolt means so as to locate and retain said stop means in a predetermined position.
 5. A timer according to claim 4 wherein said stop means further includes support means engaging said cover plate to further locate and retain said stop means.
 6. A timer according tO claim 1 wherein the other of said two members is a gear of said means coupling said drive means to said shaft means.
 7. A timer according to claim 6 wherein said clutch means includes a pair of spring washers, each carried on said shaft means, one each engaging a face of said gear.
 8. A timer comprising: a. a housing including a cup-shaped member and a cover adapted to close the same, b. a cam programming means including a shaft means carrying at least one cam, c. retaining means integrally formed with said housing, d. at least two contact blades carried by said retaining means so as to cantilever said contact blades, electrical contacts carried by said contact blades and adapted to engage one another, e. cam follower means carried by one of said contact blades responsive to said cam programming means, f. contact blade stop means disposed at the free ends of said blades, g. motor drive means including a gear carried by said shaft adjacent said cam and clutch means said motor drive means applying power driven rotation to said shaft, and h. a ring shaped stop means sandwiched between said gear and said cam, and a lug carried by said cam cooperatively engaging a stop arm projecting from said ring shaped stop means to limit the rotation of said shaft means.
 9. A timer according to claim 8 wherein at least one of said contact blades include elongated centrally disposed apertures.
 10. A timer according to claim 8 wherein said contact blades are L-shaped, and at least one of said blades includes an elongated centrally disposed aperture extending past said bend.
 11. A timer according to claim 9 wherein said contact blade retaining means comprises: an L-shaped seat formed in said cup shaped member, and L-shaped seat and a rectangular shaped member extending from said cover, and notches formed in said cup shaped member adapted to receive said L-shaped seat and said rectangular shaped member extending from said cover, insertion of said seat and said rectangular shape member in said notches providing slots receiving said contact blades to cantilever the same; and wherein said blade stop means comprises a stepped seating member extending from said cover, and notches and an L-shaped seat member formed in said cup shaped member, insertion of said stepped seating member into said notches providing a slot between said stepped seating member and said L-shaped seat member, said stepped seating member disposed to receive and stop at least one free end of said contact blades, and said slot adapted to receive an additional contact blade. 